They have to. Their species evolved less by natural selection than by glass-blowing, harsh sunlight re-shaping their organs, DNA compacting into crystal.

A uniform seven feet tall, their limbs chime quietly as they move across the surface. Thoughts flow in silent etchings across their skin; everyone can see through everyone.

The social implications are obvious.

Attempts at outside communication have not gone well. Carbon-based envoys tend to evaporate, while Mercurial ambassadors always shatter. This naturally led to tensions, but they remained manageable, until orbital surveys hinted at the planet's unexploited mineral wealth.

Every colonist remembers what happened next.

The barrage of stained-glass missiles, breaking on impact, the rainbows in the shape of mushroom clouds. The oxygen supplies, now filled with shards.